Finding the Fourth Proportional to 1,175.72, 1,622.42 and 644.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,175.72 : 1,622.42 = 644.50 : x
2. Step 2: Convert to fraction form
   1,175.72/1,622.42 = 644.50/x
3. Step 3: Cross multiply
   1,175.72x = 1,622.42 × 644.50
4. Step 4: Simplify right side
   1,175.72x = 1,045,645.22
5. Step 5: Solve for x
   x = 1,045,645.22/1,175.72
6. Step 6: Final answer
   x = 889.37